This invention relates to apparatus for grinding the edges of like sheetlike articles, such as glass sheets. More particularly, this invention relates to apparatus for grinding the edges of irregularly shaped sheetlike articles to close dimensional specifications on a repetitive basis.
Irregularly shaped planar articles, such as glass articles, are often subjected to an edge grinding operation to impart a suitable surface texture to the edge of the article and to bring the article to its final dimensional specifications. Apparatus for performing such an edge grinding operation is usually designed to be able to process irregularly shaped articles for maximum flexibility in a manufacturing operation. In such apparatus, a rotatable grinding wheel is caused to rotate about its central axis as the article being processed is rotated about its axis to permit the grinding wheel to successively engage all portions of the periphery of the article. The grinding wheel is maintained in engagement within the article by the engagement of a cam follower portion of the grinding apparatus with a precisely machined template in the desired configuration of the article being processed.
Compensation for normal wear of an edge grinding wheel during a production run can be obtained by using a cam follower with a tapered or frustoconical external configuration to follow the outline of the template, and by gradually translating the cam follower with respect to the template along the central axis of the cam follower from its larger diameter toward its smaller diameter during the production run. Such an advancement of a tapered cam follower makes it possible to maintain a constant grinding wheel position at the grinding location, notwithstanding a reduction in the diameter of the grinding wheel as a result of wear.
Heretofore, the use of a tapered, axially translatable cam follower usually required that the spindle containing the cam follower be mounted on a sliding bracket separate from the spindle used to rotatably support the grinding wheel. However, such sliding arrangements can gradually lead to wear on the elements thereof, and this, in turn, can undesirably affect the position of the grinding wheel.
Further, in apparatus of the type described above, the grinding wheel and the cam follower of prior art edge grinding devices have been mounted on opposite sides of the sheet being processed, on separate spindles with separate axes which are intended to be coaxial. However, in a long production run, these axes are subject to becoming misaligned, with another source of dimensional error in the articles being processed.